Magnetic resonance imaging and neurological recovery in acute spinal cord injury: observations from the National Acute Spinal Cord Injury Study 3

Study design: Data are from a multicenter, randomized, double blind clinica l trial of acute spinal cord injury. Objectives: To evaluate the prognostic value of magnetic resonance imaging (MRI) for randomized patients in the National Acute Spinal Cord Injury Stud y 3 (NASCIS). Setting: Sixteen spinal cord injury centers throughout the United States an d Canada. Methods: Of 499 patients randomized in NASCIS 3 between December 1991 and S eptember 1995, MRI was electively done on 191 patients within 72 h of injur y. Indications of hemorrhage, edema, and contusion were recorded by standar d protocol. Neurological impairment as determined by motor function, respon se to pin prick and light touch was assessed at admission to the participat ing center and 6 weeks after injury. Change in neurological function was ob tained by subtracting the score of each neurological parameter at admission from that measured at 6 weeks. Spinal cord surgery performed within the 3 days after injury was noted. Data were analyzed by: chi square? analysis of variance, multiple logistic regression and linear regression models. Results: Patients with hemorrhage were much more likely to have a complete injury (OR=2.88, 95 Cl 1.32, 6.23); however this association was much reduc ed when the initial neurological examination was taken into account (AOR = 1.43, 95% Cl 0.55, 3.73) and was no longer a significant predictor of injur y. MRI evidence of cord edema was the strongest predictor of reduced improv ement in motor function (-3.34 points, P= 0.06) and light touch sensation ( -3.41 points, P=0.05) at 6 weeks. Conclusions: Cord hemorrhage, contusion, and edema on MRI were not associat ed with diagnosis of a complete cord injury after neurological assessment f rom the initial clinical examination was taken into account. Prediction of a worse 6 week neurological status was weakly associated with the presence of edema diagnosed by MRI. As MRI technology improves, these diagnostic and predictive capabilities need to be re-assessed. Sponsorship: NASCIS 3 was funded by the National Institute of Neurological Disorders and Stroke at the National Institutes of Health, Washington, DC, USA. Pharmacia and Upjohn provided study drugs and placebos; they also moni tored data quality, and funded additional tests, in accordance with Food an d Drug Administration regulatory requirements. Dr Bracken has served as an occasional paid consultant to Pharmacia and Upjohn.